Universal water heater control



J n 12, 1 5 G. P. GREENAMYER 2,750,115

UNIVERSAL WATER HEATER CONTROL Filed Dec. 16, 1950 3 Sheets-Sheet 1 [/716/7 50/" ameea x? GKEF/VAMYER June 12, 1956 cs. GREENAMYER UNIVERSALWATER HEATER CONTROL 5 Sheets-Sheet 2 Filed Dec. 16, 1950 [/7 V6 for$50566 F kf-WAMYFR' 5% A 223/.

June 12, 1956 G. P. GREENAMYER UNIVERSAL WATER HEATER CONTROL 3Sheets-Sheet Filed Dec. 16, 1950 G'FORGF A G'ka-W AMYER United StatesPatent 2,750,115 UNIVERSAL WATER HEATER CONTROL George P. Greenamyer,Monrovia, Califl, assignor to General Controls Co., Glendale, Califi, acorporation of California Application December 16, 1950, Serial No.201,082 15 Claims. (Cl. 236-21) This invention relates to a universalsafety temperature control unit for automatic storage type water heatersand other gas burning heating appliances, and is more particularlyconcerned with the provision in a unitary device of a thermostaticallycontrolled valve and a thermomagnetic safety pilot valve.

' The principal object of my invention is to provide a thermostaticallycontrolled valve in which the tempera ture setting lever, that isarranged to be oscillated between the hot and cold extremes and be setat a selected position according to the temperature desired, carries anactuator reciprocable relative to it for resetting the safety pilotvalve and moving the associated armature to an attracted position inrelation to its cooperating magnet, the actuator being reciprocable forsuch operation of said 'valve only in the off or cold extreme positionof the temperature setting lever, thereby dispensing with the necessityfor a separate push-button for resetting purposes, and accordinglysimplifying operation for the user and improving the constructiongenerally.

Another object is to provide a complete universal automatic control ofsimpler and more compact design adapted for installation on a waterheater tank as a concealed control within the confined space generallyavailable for insulation, and yet so arrange the component parts of thecontrol for easy access to the snap-action valve for cleaning by simpleremoval of a closure cap provided on the outer end of the control. Theconstruction is, furthermore, so designed to facilitate molding, coringand machining, with a view not only to lower cost of production but alsomuch closer uniformity and accuracy of construction and greaterdependability in performance.

The invention is illustrated in the accompanying drawings, in which-Fig. 1 is a view partly in side elevation, but mostly in longitudinalsection on the line 1-1 of Figs. 2 and 3, showing a universal safetytemperature control unit made in accordance with my invention;

Figs. 2 and 3 are cross-sections on the lines 2-2 and 3-3, respectively,of Fig. 1;

Fig. 4 is a top view of a portion of Fig. 1, showing some of thegraduations on the valve body relative to which the pointer movable withthe temperature setting lever is arranged to move;

Fig. 5 is a sectional detail of the shut-off cock taken on line 5-5 ofFig. 3;

Fig. 6 are sectional details on line 6-6 of Fig. 1, showing on and offpositions of the shut-01f cock;

Fig. 7 is a face view of the snap-action disk provided in thethermostatically controlled valve, and

Fig. 8 is a sectional detail on line 8-8 of Fig. 2.

The same reference numerals are applied to corresponding partsthroughout these views.

Referring to the drawings, the thermostatic control .valve forming apart of the present unit is similar to those forming the subject matterof Grayson Patents 1,699,468, 1,744,465, and 1,781,328, and comprises athermostat 9 of the rod and tube type, in connection with which thetemperature setting lever 10 is provided fixed to one end portion of therod 11 to turn it relative to the tube 12 and, accordingly, adjust thethreaded end portion 13 of the rod in the plug 14 provided in the outerend portion of the tube 12. The tube 12 isof brass or copper and expandsand contracts appreciably with temperature 2,750,115 Patented June 12,1956 ice change, whereas the rod 11 is of Invar, or some other suitablenon-expanding material or one having a low coefficient of expansion. Thetube 12 is threaded, or otherwise suitably fixed, in a plug 15 that isadapted to be threadedv into a bushing or spud in the side wall of thetank of a gas operated water heater, for example. The valve body 16,which is suitably cast integral with the plug 15, has temperaturegraduations 17 provided on a cylindrical portion thereof, and thetemperature setting lever 10 has a pointer 18 thereon arranged to moverelative to these temperature graduations, as shown in Fig. 4. Thesegraduations include at the low temperature end the reading off, toindicate to the operator the extreme position to which the lever 10 hasto be moved to set or reset the safety valve 19 in open position. Thesafety valve 19, as clearly appears in Fig. 2, is provided on a rod orstem 20 reciprocable in guides 21 and 22, guide 21 being a hole in thewall of body 16, whereas guide 22 is in a plate 23 that has a press fitin a counterbore in the mouth of a cup 24 that is threaded in an opening25 provided in the body 16. A gas seal 26, which includes an O-ring fora more elfective sealing action, is provided, having a press fit in acounterbore adjacent the hole 21. A gasket 27 prevents leakage at thethreaded connection 25. The plate 23 serves also as an abutment for thelarge end of a conical compression spring 28, whose small end encirclesthe rod 20 under valve 19. This spring normally tends to close the valve19 on its seat 29, whereby to shut off the flow of gas from the line toboth the pilot burner and main burner of the storage type water heateror other gas burning heating appliance in connection with which mycontrol unit is used, the gas inlet connection being shown at 30,suitably screened, as indicated at 31, and communicating through a port32 with the safety valve. Passage 33 cored in the body 16 leads from thesafety valve through a shut-01f cock 34 to the valve chamber 35, inwhich the thermostatically controlled valve 36 is provided, arranged tobe opened and closed with snap-action in response to a predeterminedtemperature change of the thermostat 9, whereby to control the operationof the main burner and, accordingly, maintain a selected temperature forwhich lever 10 was set. Valve 36 is guided by means of a stem 37 workingin a central guide 38 provided in a bushing 39 threaded in a bore 40opening 0E valve chamber 35, this bushing having a valve seat 41 thereonfor cooperation with valve 36, and having a series of holes 42 thereinthrough which gas is free to flow into chamber 43 and, thence, throughoutlet 45 to the main burner when the valve 36 is unseated. A conicalcompression spring 46 cooperates with valve 36 to hold it normallyseated, and this spring is seated in a depression 47 provided thereforin a closure cap 48 threaded in an opening 49 provided in the wall ofthe body 16 at chamber 35. A gasket 50 prevents gas leakage at this cap.Independently of the opening and closing of valve 36, however, gas isalways supplied to the pilot burner from chamber 35 so long as thesafety valve 19 remains open, there being a passage 51 in the body'16communicating with a port 52 in the shut-off cock 34 when the cock isturned to the on or open position shown at the left in Fig. 6, throughwhich gas is con ducted to the outlet 53 and, thence, to the pilotburner,

so long as the shut-off cock 34 controlling the flow of An armature 56is carried on the inner end of the rod.

20 in a fixed coaxially spaced relationship to the safety A is valve 19and is arranged to be held by a horseshoe magnet 57 in the positionshown in Fig. 2, holding the safety valve 19 open against the resistanceof its closing spring 28, but only so long as the magnet 57 remainsenergized by current generated by the heat of the flame of the pilotburner after the pilot burner is lighted. The thermoelectric generatoris not shown but only the energizing coil 58 associated therewith andencircling the two prongs of the horseshoe magnet 57, the end portion ofthe instilated lead wire extending from the generator being. indicatedat 59 sheathed in a lead tube 6t attached, as indicated' at 61, to theneck 62 of the cup 24, the wire 59 being electrically connected with theinsulated end of the coil 58, and the other end of the coil beinggrounded. Assuming the valve 19' has been held open manually in thenovel manner of my invention hereinafter described until the armature 56is held by the magnet with sufficient force to overcome the valveclosing force of spring 28, it then is safe to supply gas to the mainburner, and the temperature setting lever 10, which, during theresetting operation, was in the OE position, as will soon appear, isswung to a selected temperature reading on scale 17. So long as lever isin the off position valve 36 will remain closed, so that there is nolikelihood of any gas being delivered to the main burner until after thepilot burner has been lighted, and, consequently, there is no likelihoodof an explosion.

In accordance with my invention an actuator 63, in the form of anelongated sheet metal stamping, is slidably mounted in a radial bore 64provided in lever 10, and is arranged to be reciprocated' by means of acap 65 that is: attached to its outer end. This cap serves as a handlefor manipulation of the actuator besides providing the pointer 18',mentioned before, and acting as an abutment and enclosure for a lightcoiled compression spring 66, which is seated in a counterbore 67 in theouter end of the lever 10. The spring 66 holds the actuator 63 normadlyin retracted position so that the radial finger 68 on the inner endofthe actuator clears the end of rod 20, permitting free swinging of thelever 10 for temperature settings. Thevalve' body 16 is cored out at theguide 21, as at 69, to provide working clearance for the inner end ofthe actuator 63 in the off position of lever 10, as clearly appears inFig. 2, so that the operator can depress the actuator against the slightresistance of spring 66 and open the safety valve 19 by engagement offinger 68- on the outer end of rod 20. It is only when the lever 10 isin the off position in line with rod and depression 69 that the actuator63 can be depressed to the extent necessary to move the valve 19 to theopen position shown in Fig. 2. In other positions of the lever 10 thefinger 68 will engagethe inside wall '70 of the connecting yoke portion71 between the-main body portion and the threaded end portion 15 andthereby limit the inward movement of the actuator 6-3 if pressure isapplied to cap 65 in that direction The lever 19 is preferably analuminum alloy die casting to save machining costs and still obtain thenicety of sliding fit needed for the actuator in the bore 64. The hubportion 72 on the lever 10 is enlarged to provide an enlarged elongatedguide 73 for the slotted intermediate yoke portion 74 of the actuator.This portion 74. has the cylindrical plunger 75 that is rigidlyconnected to the inner end of the thermostat rod 11 extending throughthe slot thereof to provide an operating connection between thethermostat 9 and the snap action mechanism for operating thethermostatic valve 36. A set screw 76 threaded in: a radial hole in thehub portion 72 fastens the lever 10 firmly to the plunger 75 and therebyconnects lever 10 with. rod 11 so that it can be threaded in onedirection or the other at 13 to adjust the thermostat accordingly for ahigher or lower water temperature.

The pointer 18 on. lever 10 will, of course, indicate reasonablyaccurately the selected temperature on the scale 17, assuming the lever10 has been set properly in relation to the rod 11 of thermostat 9 atthe factory, the lever 10 havingthescrew 76 therein for locking the samein a fixed relationship to the plunger 75 for that purpose. Plunger 75is fixed on the end of the rod 11 of the thermostat and is slidable in ahole 77 in the back wall of the body 16 for cooperation with thesnap-action mechanism for operating the valve 36. An O-ring 78, providedin an annular groove in the plunger 75, prevents gas leakage throughhole 77. A hardened steel ball 79, set in a recess in the inner end ofplunger 75, provides an anti-friction bearing for the plunger 75 on thecenter of a larger cylindrical push-member 80 that is guided for a smallamount of reciprocatory movement in a bore 81 provided in the bushing39. A circular knife edge 82 is provided on the inwardly projecting rimof the push-member 80 for engagement with the back of a convexo-concavesnap-action spring disk 83 near the outer periphery thereof, so that thedisk, which is supported at its outer peripheral. edge in the bushing 39at the inner end of the bore 81, is caused to snap over center to openthe valve 36 upon a predeter mined movement of the push-member 80 inresponse to a predetermined temperature change of thermostat 9,similarly as in Grayson Patent No. 1,699,468. However, in the presentconstruction, the disk 83 is cut away, as at 84, on opposite sides of adiametrically extending web portion 85, as illustrated in Fig. 5, so asto permit gas flow through the disk when the valve 36 is opened, andaccord ingly permit disposition of the disk right next to the valveinstead of at somev appreciable distance from it, similarly as inGrayson Patent No. 1,941,795, for greater compactness and economy inconstruction. The push-member 80 has a. series of apertures 86 providedtherein through which the gas can fiow readily into passage 43 wheneverthe valve 36 is opened. The web portion of the disk is cut transverselythrough the middle, as indicated at 87 in Fig. 7, whereby to define twoopposed radial fingers 88, the inner ends of which have abutment withthe screw 89 provided on the inner end of the stem 37 of the valve 36,the fingers 88 being adapted to give the valve 36 the maximum openingmovement in the snap-action of the disk, greater than what would beafforded if the web 85 were continuous. In other words, with the presentconstruction of the disk only the annular marginal portion 90 of thedisk is relied upon for the spring snap-action.

I claim:

1. In a thermostatically controlled valve associated with a main burnerand a pilot burner and comprising a casing, a thermostat includingthreadedly adjustably connected parts the adjustment of which determinesa selected temperature which the thermostat is to function to maintain,a thermostatic valve in said casing for controlling flow of. fueltherethrough to the main burner and operatively connected with thethermostat to be opened and closed in response to temperature change,said casing having a bypass passage leading to the pilot burner tosupply fuel thereto continuously, a safety valve adapted to shut off theflow of fuel to both burners and having an operating stern, a closingspring for said safety valve, an armature movable in a fixedrelationship to said safety valve, a magnet to attract said armaturehaving thcrmo-electric means for energization thereof responsive to theheat of the flame of the pilot burner, and an elongated temperaturesetting. lever fixed at one end to one of the aforesaid threadedlyconnected parts to turn the same for temperature adjustment and adaptedto be turned to a low temperature position in which it is directedtoward said stem of said safety valve, said lever carrying a partmovable manually lengthwise relative to the free end of said lever onlyin the low temperature extreme position thereof, arranged to engage saidstern and give corresponding lineal movement directly to the safetyvalve to open the safety valve in such movement.

2.- In a thermostatically controlled valve associated with. a mainburner and a pilot burner and comprising a casing, a thermostatincluding threadedly adjustably connected parts the adjustment of whichdetermines a selected temperature which the thermostat is to function tomaintain, a thermostatic valve in said casing for controlling flow offuel therethrough to the main burner and operatively connected with thethermostat to be opened and closed in response to temperature change,snap-action mechanism interposed between the thermostat and saidthermostatic valve to open and close the valve abruptly upon apredetermined temperature change, said casing having a bypass passageleading to the pilot burner to supply fuel thereto continuously, asafety valve adapted to shut off the flow of fuel to both burners andhaving an operating stem, a closing spring for said safety valve, anarmature movable in a fixed relationship to said safety valve, a magnetto attract said armature having thermo-electric meansfor energizationthereof responsive to the heat of the flame of the pilot burner, and anelongated temperature setting lever fixed at one end to one of theaforesaid threadedly connected parts to turn the same for temperatureadjustment and adapted to be turned to a low temperature position inwhich it is directed toward said stem of said safety valve, said levercarrying a part movable manually lengthwise relative to the free end ofsaid lever only in the low temperature extreme position thereof,arranged to engage said stem and give corresponding lineal movementdirectly to the safety valve to open the safety valve in such movement.

3. In a thermostatically controlled valve, a valve body having athermostat in assembled relationship thereto to operate a thermostaticvalve therein, said thermostat including a manually oscillatableelongated temperature setting lever adapted to be turned topredetermined posi tions about its axis of operation for selectedtemperatures and also adapted to be turned relative to said axis to alow temperature position for safety valve operation, a safety valvehaving a rod for operating the same to open position, and a part movablemanually lengthwise relative to and independently of said lever andradially relative to the aforesaid axis only in the low temperatureextreme position of said lever arranged to engage and give correspondinglineal movement directly to said rod to open said safety valve.

4. In a fuel valve structure for controlling the flow of fuel to a mainburner and a cooperating pilot burner, a casing having a valve operabletherein with a snapaction mechanism and connected to turn the mainburner on and off, a thermostat operatively associated with saidsnap-action mechanism, a spring-closed safety valve controlling bothburners and having means dependent upon the continued burning of fuel atthe pilot burner for holding the safety valve releasably in openposition, a threaded temperature adjustment for said thermostat, anelongated manually operable temperature setting arm connected to saidadjustment adapted to be turned to predetermined positions about itsaxis of operation for selected temperatures and also adapted to beturned relative to said axis to a low temperature position for safetyvalve operation, and an operator for the safety valve shiftable withsaid temperature setting arm and movable lengthwise of said arm andradially with respect to the aforesaid axis to engage and givecorresponding lineal movement directly to the safety valve to open saidvalve only when said arm is swung to a predetermined position directedradially from the aforesaid axis toward the safety valve andcorresponding assuredly to a closed position of the snap-actionthermostatic valve.

5. In a fuel valve structure for controlling the fiow of fuel to a mainburner and a cooperating pilot burner, a casing having therein a fuelinlet passage in which is included a seat for a safety valve, a safetyvalve arranged to engage said seat and having spring means normallytending to close it and an armature for holding it open arranged to beattracted by a thermo-electrically energ-izable magnet operated inresponse to heat in the operation of the pilot burner, said casinghaving an outlet passage communicating with the pilot burner fordelivery of fuel thereto whenever the safety valve is open,

said casing also having a bore therein with which an outlet portcommunicates for delivery of fuel to the main burner, a temperaturecontrol valve in said casing arranged to open and close in response totemperature change, a thermostat operatively connected with saidtemperature control valve and having a rotatable temperature settingadjustment, a rod attached to and reciprocable with the safety valve andguided for movement in a direction in transverse relation to and spacedfrom the rotatable temperature setting adjustment, a temperature settinglever connected with said temperature seting adjustment to operate thesame by oscillation of said lever, and an operator for said safety valveshiftable with the temperature setting lever in the oscillation thereofand operable when said lever is in a low temperature extreme position tomove the safety valve to and hold it temporarily in open position.

6. In a fuel valve structure for conrolling the flow of fuel to a mainburner and a cooperating pilot burner, a casing having therein a fuelinlet passage in which is included a seat for a safety valve, a safetyvalve arranged to engage said seat and having spring means normallytending to close it and an armature for holding it open arranged to beattracted by a thermo-electrically energizable magnet operated inresponse to heat in the operation of the pilot burner, said casinghaving an outlet passage communicating with the pilot burner fordelivery of fuel thereto whenever the safety valve is open, said casingalso having a bore therein with which an outlet port communicates fordelivery of fuel to the main burner, a temperature control valve in saidcasing arranged to open and close in response to temperature change, arod and tube type thermostat operatively connected with said temperaturecontrol valve and having a temperature setting adjustment operable witha threading action, a rod attached to and reciprocable with the safetyvalve and guided for movement in a direction in transverse relation toand spaced from the thermostat, a temperature setting lever connectedwith said temperature setting adjustment, and an operator for the safetyvalve which is manually operable and guided for reciprocatory movementon the temperature setting lever but held against such movement in allbut the low temperature extreme position of said lever, whereby topermit manual opening of the safety valve only in that position of saidlever.

7. In a thermostatic temperature control valve for a gas appliance, suchas a storage type water heater, comprising a valve body having a yokeextension carrying on it a threaded plug adapted for rigid connectionwith the appliance, a thermostat supported on said plug having athreaded temperature adjustment, a valve in said body connected withsaid thermostat for operation, and an elongated temperature settinglever connected with said thermostat temperature adjustment andoscillatable relative to said yoke, the improvement which consists inthe provision of a safety valve connected in series with saidthermostatic valve to control fuel flow through said valve bodyindependently of said thermostatic valve, said safety valve having anoperating stem, and a part carried upon and movable manually lengthwiserelative to and independently of said temperature setting lever when itis substantially in alignment with said operating stem in the lowtemperature extreme position of said lever arranged to engage saidoperating stem and give corresponding lineal movement directly to thesafety valve to open said safety valve.

8. In a thermostatic temperature control valve for a gas appliance, suchas a storage type water heater, comprising a valve body having a yokeextension carrying on it a threaded plug adapted for rigid connectionwith the appliance, a thermostat supported on said plug having athreaded temperature adjustment, a valve in said body connected withsaid thermostat for operation, and an elongated temperature settinglever connected with said thermostat temperature adjustment andoscillatable relative to said yoke, the improvement which consists inthe provision of a safety valve connected in series with saidthermostatic valve to control fuel flow through said valve bodyindependently of said thermostatic valve, said safety valve having anoperating stern, and an operator for the safety valve which is manuallyoperable and guided for reciprocatory movement lengthwise on thetemperature setting lever and independently thereof to engage saidoperating stem and give corresponding lineal opening movement to thesafety valve, said operator being held against such movement in all butthe low temperature extreme position of said lever, whereby to permitmanual opening of the safety valve only in that position of said lever.

9. In a universal automatic thermostatic control suitable for storagetype water heaters, the combination of a thermostat, a valve body, oneend of which is constructed for connection to the tank of the heater andthe other end of which provides a housing containing a snap-action valveoperable by means of the thermostat, a safety valve arranged between theends of said valve. body together with manually operable means forsetting the same, said thermostat including an elongated lever shiftableto different positions for selection of desired temperatures, and saidlast named means being shiftable with said lever and operable lengthwiseonly in a low temperature setting thereof, so that the safety valve isnot openable in other positions of said lever.

10. In a universal. automatic thermostatic control suitable for storagetype water heaters, the combination of a thermostat, a valve body, oneend of which is constructed for connection to the tank of the heater andthe other end of which provides a housing containing a' snap-actionvalve operable by means of the thermostat, a safety valve arrangedbetween the ends of said valve body together with manually operablemeans for setting the same, said thermostat including an elongated levershiftable to different positions for selection of desired temperatures,and said last named means being shiftable with said lever andreciprocable lengthwise relative thereto to open the safety valve onlyin a low temperature setting thereof, so that the safety valve is notopenable in other positions of said lever.

11. In a universal automatic thermostatic control suitable for storagetype water heaters, the combination of a thermostat, a valve body, oneend of which is constructed for connection to the tank of the heater andthe other end of which provides a housing containing a snapact'ionval've operable by means of the thermostat, a safety valve arrangedbetween the ends of said valve body, said safety valve having anoperating stem, manually reciprocable means arranged to engage andtransmit lineal opening movement to said safety valve in directproportion to the lineal movement given said means when said means ismoved radially relative to an axis of rotation, said means beingconnected with the thermostat for selection of a desired temperature byrotary movement of the samemeans about said axis.

12. A universal temperature control of the character described for usein connection with a main burner, a pilot burner therefor, and a safetyvalve controlling the flow of gas to both of said burners, said safetyvalve having an o erating stem, a thermostat, a valve body having athermostatic valve operable therein by means of the thermostat tocontrol the flow of gas to the main burner, and a temperature settingmeans which is rotatable about an axis and movable radially with respectto said axis and is connected with said thermostat, which said meanswhen turned about said axis of. rotation clos- P ing. the thermostaticvalve and when moved radially relative to said axis engaging said stemand giving corresponding lineal opening movement directly to the safetyvalve so that'n'o gas may flow to the main burner until thepilot burneris lighted;

13. A universal temperature control of the character described for usein connection with a main burner, a pilot burner therefor, and a safetyvalve controlling the flow of gas to both of said burners, a valve bodyhaving a thermostatic valve operable therein by means of a th'emrostatto control the fiow of gas to the main burner, and a temperature settingmeans which is rotatable about an axis and also movable radiallyrelative to said axis, said means being so connected with saidthermostat and thermostatic valve and so operatively related to saidsafety valve that when said means is turned about the axis of rotationthe thermostatic valve is closed and when said means is moved radiallyrelative to said axis the safety valve is opened so that no gas may flowto the main burner until the pilot burner is lighted, there being springmeans tending to close the safety valve, and thermo-electric meansoperable in response to the heat of the flame of the pilot burner forholding the safety valve open against the action of said spring means.

14. In a universal fuel control for use in connection with a mainburner, a pilot burner therefor, and a safety valve controlling the fiowof gas to both said burners, said safety valve having an operating stem,the combination of a snap-action valve operable by a thermostat forautomatically controlling the flow of gas to the main burner, whereby toregulate the temperature of the medium heated thereby, electro-magneticmeans operating the safety valve in response to heat of the flame of thepilot burner to keep said safety valve open only so longv as the pilotburner is not extinguished, a rotatable means turnabl'e about an axisand connected. with the thermostat to set the same for a desiredtemperature, said means including a reciprocable means movable radiallywith respect to the aforesaid axis and arranged to be connected directlywith the safety valve by engagement with the operating stem thereof togive corresponding lineal movement thereto to open the safety valve inthe low temperature'extreme position of said rotatable means.

15. In a fuel valve structure for controlling the flow of fuel to a mainburner and a cooperating pilot burner, a casing having therein a fuelinlet passage in which is included a seat for a safety valve, a safetyvalve arranged to engage said seat and having spring means normallytending to close it and an armature for holding it open arranged to beattracted by a thermo-electrically energizable magnet operated inresponse to heat in the operation of the pilot burner, said casinghaving an outlet passage communicating with the pilot burner fordelivery of fuel thereto whenever the safety valve is open, said casingalso having a bore therein with which an outlet port communicates fordelivery of fuel to the main burner, a temperature control valve in saidcasing arranged to open and close in response to temperature change, athermostat operatively connected with said temperature control valve andhaving a rotatable temperature setting adjustment, a rod attached to andreciprocable With the safety valve and guided for movement in adirection in transverse relation to and. spaced from the rotatabletemperature setting adjustment, a temperature setting lever connectedwith said temperature setting adjustment to operate the same byoscillation of said lever, and an operator for the safety valve which ismanually operable and guided for reciprocatory movement on thetemperature setting lever but held against such movement in all but thelow temperature extreme position of said lever, whereby to permit manualopening of the safety valve only in that position of said lever.

References Cited in the file of this patent UNITED STATES PATENTS BrownSept. 1, 1953

